Venting GF and Air Conditioning Question :)

I am thinking of moving my GF to a different room and that room is upstairs with the window directly above the two air conditioner units on the ground outside. My limited knowledge of air conditioners is that that air is taken in from inside the house and blown out of the units outside. I am correct to assume that it would be alright to vent my GF out of the window above these outside units? I live in South Florida and we run our AC all day and night 365 days a year, just want to double check that I won’t be taking in any of the GF exhaust from these outside AC units.

1 Like

You are correct, the outside unit just heat exchanges.

4 Likes

i literally vent out the GF and the heat exchange from my portable AC about 10" apart. it’s not a problem.

4 Likes

I do not think your understanding is correct. Central air units, usually knows as split units, don’t mix outside and inside air. The connection between the two units is only through the transfer of thermal energy in the refrigerant. The inside unit pulls air from inside the house, runs it through a heat exchanger, and then pushes it back into the house. The outside unit does the same thing, except its air is only outside the house.

An A/C unit should always pull from the house since that air will be cooler and therefor take less energy to cool than pulling from the outside. Any venting should be hotter air from the heat exchanger and should only vent outside with no outside air input.

1 Like

Note, I’m assuming you’re talking about central air and not a window unit…

The AC unit outside makes cold water which circulates inside in a closed loop. The AC unit extracts heat from the water, making the water colder and exhausting the removed heat via its big fan. The cold water is pumped to a “heat exchanger” located in the ductwork for the heating/cooling system inside the house. Air gets sucked in from inside the house and passed through the heat exchanger and then exhausted back in to the house. The “air balance” of the house should be zero, meaning it is at the same pressure inside as it is outside. Especially in Florida, you don’t want to let any air from outside get inside. Some is going to get in anyway, but too much just means the AC runs all the time. And you don’t want air from inside getting out since that’s just air conditioning the outside.

So run your GF exhaust wherever you want, the AC isn’t going to care. Just beware that the GF is going to pump air from inside the house to the outside. That’s going to change the air balance, the house will be at lower pressure and outside air will be drawn in. If the easiest place to suck air in is anywhere near your exhaust you may have a problem drawing fumes back in to the house. So make sure the area around the exhaust is as airtight as you can make it. With the house closed up tight it could make a difference. (I have a place in Ocala, BTW. Though I’m in the NE more often than not of late).

This is correct, except that most AC units don’t use water as it not as efficient a heat transfer medium as the refrigerant that is used. Most refrigerant is a chemical with lower evaporation temperature than water so that you can dump more heat into it at a lower temperature. Water doesn’t work all that well without some pretty high temperature differences because it won’t evaporate, which is what does the best at cooling.

1 Like

Because ventilation is complex and poor ventilation could cause smelly and even dangerous results, we can’t advise on exhaust configurations other than what’s described in the Glowforge Manual at https://glowforge.com/manual.
I am going to move this topic to the Beyond the Manual section so that you can talk further.

Don’t usually mix outside and in. There are systems that have a mode where you can exchange the air in the house with fresh air from outside, but generally if you have this, you’ll know it – it’s more common on fancier setups.

1 Like

This topic was automatically closed 30 days after the last reply. New replies are no longer allowed.